Обсуждение: pgsql/src/backend/optimizer/path joinpath.c

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pgsql/src/backend/optimizer/path joinpath.c

От
Tom Lane
Дата:
CVSROOT:    /home/projects/pgsql/cvsroot
Module name:    pgsql
Changes by:    tgl@hub.org    01/04/14 20:48:17

Modified files:
    src/backend/optimizer/path: joinpath.c

Log message:
    Prevent generation of invalid plans for RIGHT or FULL joins with multiple
    join clauses.  The mergejoin executor wants all the join clauses to appear
    as merge quals, not as extra joinquals, for these kinds of joins.  But the
    planner would consider plans in which partially-sorted input paths were
    used, leading to only some of the join clauses becoming merge quals.
    This is fine for inner/left joins, not fine for right/full joins.